Lately I have been using the yoga blocks to realign students posture. When I first learnt half moon pose, I balanced well on my standing foot, but I would tilt slightly towards the floor. Instead I teach the students to use the blocks while doing ardha chandrasana. This helps them from straining their lower back to carry their upper half of the back should they tilt forward.
Lord of the dance or Natarajasana, one of my favourite yoga poses, helps open the chest and hips. I like it personally cause it makes me feel 'light'.